Fire-extinguishing apparatus



Aug. 28, R. W AU$T|N FIRE-EXTINGUISHING APPARATUS Filed Dec. 15 1951INVEN TOR. /7%4 W 14057727 BY QZ MQLLQQ 4 TTOFFNE Y FIRE-EXTINGUISHIN GAPPARATUS Ralph W. Austin, Weymouth, Mass, assignor to ProcessEngineering Inc., Somerville, Mass., a corporation of MassachusettsApplication December 13, 1951, Serial No. 261,424

1 Claim. (Cl. 169-31) This invention relates to fire-extinguishingapparatus.

One object of the invention is to provide a novel fire extinguisherwherein an extinguishing medium is stored within a gas-pressurizedsealed extinguisher casing toforma sealed unit and wherein the sealedextinguisher casing is detachably supported in operative relation togasreleasing mechanism, and preferably in operative relation toseal-puncturing mechanism; to thereby permit the sealed extinguishercasing and the gas-releasing mechanism to be readily detached from oneanother for. replacement and recharging purposes.

Another object of the invention is to provide a novel fire extinguisherwhich is highly efiicient in operation, lightin weight, maybe easily andconveniently assembled, andin which one or more component parts and/orthe entire extinguisher are expandable, as will be described.

A further object of the invention is to provide a novel fireextinguisher in which the extinguishing medium is maintained underpressure within the extinguisher casing, and principally in liquid form,and comprises a plurality of components which are metered to the vaporphase States Patent when the pressure is released and the extinguisheris operated.

With these general objects in view and such others as may hereinafterappear, the invention consists in the fireextinguishing apparatushereinafter described and particularly defined in the claim at the endof this specification.

In the drawing I have illustrated in the single Figure in elevation,with portions in section, the preferred form of fire-extinguishingapparatus embodying the invention.

In general, the present invention contemplates a novelfire-extinguishing apparatus in which an extinguishing medium is storedwithin a gas-pressurized extinguisher casing to form a sealed unit. Theextinguishing medium itself may comprise any usual or preferred form ofextinguishing medium, such as known dry chemicals, known liquids whichmay be discharged as a gas or as a liquid, and also certain knownextinguishing gases themselves. The gas-pressurized sealed extinguishercasing unit is detachably supported in operative relation togas-releasing mechanism and preferably to seal-puncturing mechanism tothereby permit the sealed casing unit and the gasreleasing mechanism tobe detached from one another for replacement, recharging and otherpurposes.

In its preferred form the extinguishing medium may comprise ahalogenated aliphatic compound characterized by the fact that at lowtemperatures and under substantial pressure it remains liquid withminimum vapor pressure, and upon release of the gas pressure the liquidis metered to the vapor phase to form an extinguishing gas. A suitablehalogenated aliphatic compound may be selected from the compoundsdisclosed in the publication of October 1951, in the National FireProtective Associations quarterly publication, and particularly in thearticle by J. Malcolm, of the Engineer Research and DevelopmentLaboratories, Ft. Belvoir, Virginia. Such a compound may and preferablywill comprise bromotrifluoromethane,

although the invention contemplates other extinguishing media, such assulphur hexachloride, carbon dioxide; or carbon tetrachloride.

For convenience of description; the halogenated a li phaticcompound usedin the present fire extinguisher as the fire-extinguishing medium willbe hereinafter referred to as halon, the trade name given tobromotri-fluorm methane and similar compounds.

As herein shown, the extinguisher is provided with extinguishing casing10 of steel or other metal having the strength to withstand the requiredpressures. The casing 10 is provided with a threaded neck 12 adaptedtobe screwed into a headindicated generally at 14. The halo'n isrefrigerated to liqu'd form, and a predetermined weight or volumethereof is introduced into the casing 10. Preferably, the casing is ofa" size such that the-quantity of halon employed-fills themajorportio'r'r of the casing. Immediately thereafter ametal sealing cap16 is welded on the upper open end of the ne'ck ofthc' casing, asuitable siphontube 18 and screen 19 having been previously assembled inoperative relation to the cap 1-6 and Welded thereto. When the cap is insealing position upon the upper endof the neck" of the casing the siphontube assumes its proper position within the. casing as shown; Prior tothe welding of the" cap upon the casing, as described, the extinguishingcasing-is pres surized' by a gaseous medium, preferably nitrogen, andinpractice, the nitrogen isdelivered into the casing at approximately220' lbs; per square inchgauge;- and because of the fact that therefrigerated liquid in the cylinder exerts little vapor pressure, it ispossible by properly welding the cap assembly to seal the mouth of theextinguisher casing to pressurize the system at from 200 to 210 lbs. persquare inch so that when the refrigerated liquid is permitted to come upto room temperature about 400 lbs. per square inch pressure will bedeveloped Within the extinguisher casing.

Referring to the drawing, it will be observed that the pressurizedcylinder or casing 10 with the cap sealed in place to hermetically sealthe same is screwed into the threaded opening in the bottom of the head14. The upper end of the cap 16 bears against a lead or equivalent capseal providing a compressible member between the shoulder portion 22 ofthe interior surface of the head 14 and the top of the cap. From thedescription thus far it will be observed that the pressurizedextinguisher casing 10 is removably secured in the lower portion of thehead and may be readily replaced when it is required to recharge theextinguisher.

The head 14 is arranged to operatively support mechanism for puncturingthe cap 16 when the extinguisher is to be operated. In general, thecap-puncturing mechanism comprises a pointed puncturing member 25 shapedwhen moved through a predetermined stroke to form a predetermined-sizedhole in the cap 16, and such opening comprises a metering opening in theoperation of the extinguisher, as will be described. Resilient means areprovided for normally maintaining the puncturing pin raised in itsinoperative or non-puncturing position. As illustrated herein, thepuncturing pin 25 is mounted on the lower end of a plunger 27 slidablymounted in a hole in the upper wall of the head 14. The plunger isprovided with a flanged portion at its lower end, and a gasket isinterposed between the flange and the undersurface of the upper wall ofhead 14, as shown. The plunger projects upwardly beyond the top of thehead, and a coil spring 30 of substantial strength embraces theprojecting portion of the plunger and is interposed between a handle 32on the upper end of the plunger and the top of the head so that when itis desired to operate the extinguisher the handle is depressedcompressing the coil spring until Patented Aug.- 28", 1956- thepuncturing pin punctures the cap and forms therein a hole of apredetermined size., When downward pres:.

sure is removed from the handle, the spring returns the parts to theposition shown. 3 After the cap has been punctured, the gas pressurewithin the cylinder forces the extinguishing liquid upwardly through thesiphon tube and through the metering hole which has been formed in thecap, and the liquid emerges from the metering hole as a gas undersubstantial pressure. This gas is discharged from the chamber 38 througha discharge orifice in a horn member 40 screwed into a threaded hole inthe side of the head 14. The stream of gas may be directed by the hornupon the fire to be extinguished.

From the description thus far it will be observed that the presentconstruction of extinguisher is simple, positive in operation, and theextinguisher may be constructed to be light in weight. The head and/ orthe casing and/ or the entire extinguisher may be expendable. Thescrewedin mounting of the easing into the head facilitates thereplacement of a casing of a discharged extinguisher with a new filledand sealed casing. In those instances Where it is desired to renew thehead, this may be also readily accomplished by reason of the screwed-inmounting. The structure of the extinguisher lends itself to use bymilitary service personnel, and the casings may be stored in depots ormobile carriers until required. All parts of the extinguisher arereadily replaceable in the field, and the parts for completion may bereadily shipped in knocked-down form and easily assembled in the field.

While it is preferred to utilize bromotrifluoromethane and nitrogen asthe two components of the present extinguisher, nevertheless, ifdesired, other extinguishing liquids having equivalent characteristicsmay be used, and in addition, one more other gas, such as carbondioxide,may be used instead of or with the nitrogen.

Having thus described the invention, what is claimed is:

A fire extinguisher comprising a casing having a threaded neck portion,said casing being gas pressurized and containing an extinguishingmedium, a puncturable cup-shaped metal cap welded upon the neck andsealing the extinguishing casing, a siphon tube leading downwardly fromthe cap into the casing and being itself Welded to the internal wall ofthe cap, said casing being partially filled with a liquid halogenatedaliphatic extinguishing compound and the remainder of the casing beingpressurized with an inert gas to a predetermined pressure, a one-piecehead portion having manually operated cap-piercing mechanism carriedthereby, said head portion being removably secured to the threaded neckportion of the casing to form a unit therewith, the interior of saidhead portion having a conical shoulder, and a gasket extended across thetop of said cap and interposed between the top of the cap and saidconical shoulder, said gasket being directly engaged with the top of thecap and with said conical shoulder.

References Cited in the file of this patent UNITED STATES PATENTS1,919,149 Mapes July 18, 1933 1,968,825 Goodall Aug. 7, 1934 2,109,966Breitmann Mar. 1, 1938 2,519,967 Jones Aug. 26, 1950 2,548,750 StroopApr. 10, 1951 2,586,088 Reeves Feb. 19, 1952

